Complex chromium compounds of azo dyestuffs



Patented June 30, 1931 UNITED STATES PATENT OFFICE ELAN S KRZIKALLA, OF MANNI-IEIM, AND FRANZ BLUEMMEL, OF SECKENHEIM, GER- MANY, ASSIGNORS TO GENERAL ANILINE WORKS, INC., OF NEW YORK, N. Y., A COR- PORATION OF DELAWARE COMPLEX GHROMIUM COMPOUNDS OF AZO DYEST'UFFS No Drawing. Application filed November 30, 1928, Serial No. 322,960, and in Germany December 1, 1927.

tained by treating the o-hydroxyazo dyestufis obtainable from diazotized o-aminophenols or their derivatives and ,B-diketones of the general formula in which R and R may be the same or diiferent alkyl-, aralkyl-, or aryl radicles, with chromium compounds capable of forming complex compounds with azo dyestuffs. The treatment may be carried out for instance by boiling or heating under pressure an aqueous solution of the dyestufi" and the chromium compound.

The resulting dyestufls may be app-lied for a great variety of purposes, such as dyeing wool and leather, or for making lakes or colored lacquers or varnishes, and are distinguished by their excellent properties as regards fastness.

The following examples will further illustrate the nature of the said invention which however is not limited thereto. The parts are by weight.

Example 1 87.6 parts of the azo dyestuflf obtainable from. diazotized l-nitro-Q-aminophenol-G-sulfonic acid and acetylacetone are boiled in an aqueous solution with 14 parts of chromium fluorid for several hours under a refluxcondenser. The dyestufi obtained on salting out is very strong and gives very fast, handsome and particularly even yellow dyeings, with a reddish tinge, on wool.

The dyestufl can also be prepared with the aid of chromium formate."

A similarly prepared chromium compound of the dyestuff obtainable from diazotized 4:- chlor-2-aminophenol-G-sulfonic acid and acetylacetone gives redder dyeings on Wool and this is also the case with the chromium compound of the azo dyestufl' obtainable from the nitrated diazo compound of 1-amino-2- naphthol= l-sulfonic acid and acetylacetone.

Ewample 2 43 parts of the o-hydroxyazo dyestufi' obtainable from diazotized l-amino-Q-naphthol- 4-sulfonic acid and benzoylacetone are boiled for about 2 hours with 16 parts of chromium fluorid and 500 parts of Water, the chromium compound of the dyestutt being then salted out. The resulting chromiferous dyestuflt' gives fast and very even red violet dyeings on WOOl. The chromium compound of the corresponding dyestulf obtainable from the nitrated diazo compound of l-amino-Q-naphtholl-sulfonie acid gives redder shades.

What we claim is As a new article of manufacture the complex chromium compound of the o-hydroxyazo dyestuff obtainable by coupling diazotized i-nitro-2-aminophenol-6-sulfonic acid and acetylacetone, dyeing wool yellow shades with a reddish tinge.

In testimony whereof we have hereunto set 7 

